Shock-absorber.



J. A. DOXEY.

SHOCK ABSORBER.

APPLICATION FILED APR. 27, I9I4.

1,170,226. Petented Feb. 1, 1916.

f7 eef-J JOHN A. DOXEY, 0F CHICAGO, ILLINOIS.

snoek-ABSORBER.

Speeication of Letters Patent.

' Patented Feb. 1, 191e.

Application led April 27, 1914. Serial No. 834,737.

To aZZ whom t may concern:

Be it known that I, JOHN A.. DoxEY, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Shock-Absorbers, ofwhich the following is a specification.

My invention relates' to a shock absorber for vehicles, moreparticularly for automobiles and the object thereof is to provide asimple, eiicient and reliable absorber opm erating on the air principle.

Speaking in general terms, my shock absorber comprises a cylinderconnected with one member of the vehicle such as the lower spring andaxle and having a piston connected with another member of the vehiclesuchhas the chassis frame and upper spring membenin case the spring isof the full elliptic, semi-elliptic or three-quarter elliptic, theparticular type or character of spring being immaterial. My shockabsorber is also provided with means for thoroughly lubricating thepiston and walls of the cylinder with oil as an incident to themovements of the piston and its cylinder in the regular operation of theshock absorber.

In the drawings Figure 1 is a central vertical sectional elevation of myshock absorber and Fig. 2 a side viewl of a part of an automobilestructure and its springs showing my shock absorber in position.

Referring to the embodiment of my invention as herein shown my shockabsorber comprises a cylinder 1 of suitable length and diameteraccording to the work to be done, that is according to the weight of theautomobile and provided with an upper head 2 and a lower head 3 whichare secured to the ends'of the cylinder in suitable manner as by screwthreading, after which the joints at the screw threads are soldered orbrazed over as shown at 4 in ordery to prevent any leakage through thescrew threads. The lower head is pr ovided with a drain opening closedby a screw plug 5 and the upper head is provided with a supply openingclosed by a screw plug 6, these openings being provided for theadmission of oil and the draining of the same respectively wheneverdesired. This cylinder is provided along one side with. a bypass 7extending from near the upper end of the cylinder to a pointSubstantially at the bottom thereof. The upper end of the cylinder isprovided with an air inlet opening 8 lformed in a valve casing 9 inwhich is arranged a suitable check valve such asa .ball 10 normallyspring-pressed against the air inlet opening 1l. The purpose ofthisvalve-controlled inlet is to supply additional air to compensate forany leakage of air from the shock absorber during the operation thereof.

Within the cylinder there travels a piston 12 which is well packed insuitable manner as by means of the piston rings 13 and the gaskets 14 ofleather or equivalent material placed on opposite sides of the piston.This piston is provided with a rod 15 which extends through a packingbox 16 formed in the upper head 2-and is secured at its inner end to thepiston. In the present instance this end of the piston rod isscrew-threaded, screwing centrally through the piston and held theretoby means of the two nuts 17 and 18 located on opposite sides of thepiston. The piston rodis provided with a by-pass 19 between suchopposite sides of the piston, such by-pass extending centrally for apart of the way througn the inner end of the piston-rod and thencelaterally to the side of the rod where it emerges at a point above thenut 18. By this arrangement a shallow body of oil indicated at 20 ispermitted on the top face of the piston and any overflow passes throughthe by-pass to the bottom of the cylinder where another body of oilindicated at 21 collects.

The shock absorber as thus described may be connected in any suitablemanner to the proper parts of the vehicle. In the present instance Ihave shown the lower head of the cylinder connected by means of a bolt22 with a bracket 23 whose horizontal portion 23a is secured to the axleand to the lower section A of the spring by the usual clips a which alsoserve to hold the leaves of the spring togethenand in place upon theaxle structure A as indicated in Fig. 2. The bolt 22 has a ball andsocket connection with the head 3 to which end the bolt has` a ball 22and the head a socket 8a, the parts being held against withdrawal bymeans of the screw plug 24. vBy preference the bolt 22 has ascrew-threaded outer end passing through the bracket 23 and removablyheld in place by means of the nut 25.

The piston rod is provided with a bolt 26 similar to the bolt 22 andhaving a ball and screw plug 27.

socket connection therewith together with a The bolt 26 is screwthreadedinto one end of a horizontal bracket 28 which is here shown as a part ofthe bracket 29 secured to the frame B of the chassis, being the samebracket to which the upper spring section C is secured by means of theclips 80.

l/Vhile lin the present instance I have shown my shock absorber asapplied to a sprin-g of the full elliptic type, it will be understoodthat its application is not limited thereto but that it may be appliedto the semi-elliptic or three-quarter elliptic as well. By preferencethe shock absorber* is applied to the springs at a point towardtheir'middle portions as indicated in F ig. 2.

My shock absorber being a construction as above described operates asfollows: Upon the downward movement of the body and chassis frame B dueto a jolt or unevenness in the road the piston rod 15 and its piston 12will be forced downwardly by the rod and weight of the vehicle but asthe piston is a closed one the air below the piston will be compressedby the downward movement of the piston, it being understood that thepassage 19 is of such small carrying capacity that it cannot pass theair to produce equilization on opposite sides of the piston. In thedownward movement of the piston and the consequent compression of theair below it a small quantity of the oil in the bottom of the cylinderwill be forced upwardly through the by-pass 7 and be ejected into thespace above the piston and onto the upper face thereof, thereby alwayskeeping a small supply or pool of oil 21. The shock absorber tends torestore the body and chassis to normal position relative to the axlestructure and tends to resist any" upward movement beyond the normal inthe same manner as on the down stroke of the piston inasmuch as thelatter on its upward movement beyond normal position compresses the airin the upper end of the cylinder. In case of anyL leakage of arlfrom ffwithin the cylinder to compensate for such loss the valve 10 will openand admit the necessary amount 0f air through the inlet Y port l1.Inthis manner and by these means the quick and violent movements andjolts imparted to the springs are absorbed and the springs therebyrelieved. At the same time during the movements of the piston the wallsof the cylinder are automatically kept lubricated, and a supply of oilis constantly mai tained in anautomatic manner on the top face of thepiston with the result that the piston is at all times'keptljpackedagainst any possible leakage.

I claim:

l. A shock absorber comprising'a closed cylinder having a by-passbetween its upper and lower ends, a piston in the cylinder having aminute open leak-pass between its opposite sides, and a charge of oilincompletely lilling the lower end of the cylinder.

2. A shock absorber comprising a cylinder having a by-pass between itsupper and lower ends, and a piston therein having an always open by-passbetween its opposite sides whose upper end communicates with thecylinder at a point slightly above the top of the piston to therebypermit oil to collect in a pool on top of the piston and to overiiowthrough said by-pass.

3. A shock absorber comprising a closed cylinder having a by-passbetween its upper and lower ends, and a piston in the cylinder providedwith a rod having an always open by-pass between opposite sides of thepiston, said latter by-pass communicating at its upper end with thecylinder at a point slightly above the top of the piston.

4. A shock absorber comprising a cylinder having a'by-pass leading fromthe extreme -lower end thereof to a point near the top of site sidespermitting leakage, and a charge of oil normally standing in the bottomof the cylinder a short distance above the level of the lower end of theby-pass, a relatively large space above the oil and below the pistonconstituting an air chamber.

5. A shock absorber comprising a cylinder having a by-passleading fromthe extreme lower end thereof to a point vnear the top of the same, apiston in said cylinder provided with packing arranged around itsperiphery and having a minute open leakpass between its opposite' sideswhose upper end communicates with the space above the piston at a pointslightly above the top of such piston to permit oil to collect in a poolon top of the piston and an overow to drain through such leak-pass, anda charge of oil normally standingin the bottom of the cylinder a shortdistance above the level of the lower end of the by-pass, a relativelylarge space above the oil and below the pist0n constituting an airchamber'.

JOHN A. DOXEY.

Witnesses i Lotus B. lERwIN, RoBER'r DOBBERMAN.

